A starter for an engine is equipped with a planetary gear train as a torque variator to change torque used to start the engine. The torque variator is capable of changing the degree of torque which is transmitted between a planetary carrier and an outer gear of the planetary gear train, thereby changing a ratio of speed of a sun gear to speed of the planetary carrier of the planetary gear train to increase or decrease the degree of torque required to start the engine. This ensures the stability in starting the engine, for example, in cold conditions and achieves a quick start of the engine as needed.

An integrated starter and generator (ISG) system of a vehicle includes: a planetary gear set including a sun gear, a planet carrier, and a ring gear as rotation elements of the planetary gear set; and an integrated starter and generator (ISG) functioning as a motor and a generator, and including a stator and a rotor. The planetary gear set and the ISG are disposed in a crankshaft pulley of an engine such that torque of a crankshaft of the engine is increased and is transmitted to the ISG when generating electricity and torque of the ISG is decreased and is transmitted to the crankshaft of the engine when starting.

An electric machine having a housing part which is in the form of a drive bearing (19), having an electric motor (13) as a drive, having a planetary gearing (153) and having a drive element (22), wherein the planetary gearing (153) has at least one planet gear (16) which meshes with an internal gear (73), and a gear carrier (95) which is coupled to the drive element (22) can be driven by means of the planet gear (160), wherein the internal gear (73) has at least one engagement element and the housing part has at least one engagement element, and the at least two engagement elements engage into one another in alternating fashion, characterized in that an intermediate bearing carrier (98) has at least one engagement element and the housing part has at least one engagement element, and the at least two engagement elements engage into one another in alternating fashion.

A method is provided to start a combustion engine in a hybrid powertrain, comprising a gearbox with input and output shafts; a first planetary gear, connected to the input shaft and a first main shaft; a second planetary gear connected to the first planetary gear and a second main shaft; first and second electrical machines respectively connected to the first and second planetary gears; one gear pair connected with the first main shaft, and therefore with the first planetary gear and the output shaft; and one gear pair connected with the second main shaft. The method comprises: a) connecting an output shaft of the combustion engine with the input shaft of the gearbox, via a coupling device arranged between the output shaft and the input shaft; and b) controlling the first and second electrical machines to start the combustion engine.

An automatic two-mode high reduction power transmission system. A power transmission system includes a first device that delivers a first input and receives a second output. A second device delivers a second input and receives a first output. A power transmission has two planetary gear sets and operates in a first mode at a first speed ratio, where the first input is received from the first device and in response, the first output is delivered to the second device. The power transmission operates in a second mode at a second speed ratio that is different than the first speed ratio, where the second input is received from the second device and in response, the second output is delivered to the first device. A pair of freewheel mechanisms automatically couple one of the first or second ii devices with the power transmission to provide the two modes.

A vehicle control system is provided which is used in a vehicle equipped with an engine as a drive power source and works to establish engagement of a pinion of a starter motor with a ring gear mounted on a rotational axis of the engine and then actuate the starter motor to start the engine. The vehicle control system executes a preset mode to move the pinion to achieve the engagement with the ring gear when the rotation speed of the engine has dropped below a given threshold value. The threshold value is determined as a function of speed of the vehicle, thereby alleviating a driver's perception about unwanted mechanical noise arising from impact the pinion on the ring gear upon the engagement therebetween.

A vehicle control system is provided which is used in a vehicle equipped with an engine as a drive power source and works to establish engagement of a pinion of a starter motor with a ring gear mounted on a rotational axis of the engine and then actuate the starter motor to start the engine. The vehicle control system executes a preset mode to move the pinion to achieve the engagement with the ring gear when the rotation speed of the engine has dropped below a given threshold value. The threshold value is determined as a function of speed of the vehicle, thereby alleviating a driver's perception about unwanted mechanical noise arising from impact the pinion on the ring gear upon the engagement therebetween.

A method is provided to start a combustion engine in a hybrid powertrain, comprising a gearbox with input shaft and output shaft; which combustion engine is connected to the input shaft; a first planetary gear connected to the input shaft; a second planetary gear connected to the first planetary gear; first and second electrical machines, respectively connected to the first and second planetary gears; at least one gear pair, connected with the first planetary gear and the output shaft; and at least one gear pair, connected with the second planetary gear and the output shaft. The method comprises connecting the rotatable components of the second planetary gear with each other by connecting, via a second coupling device, a second sun wheel arranged in the second planetary gear and a second planetary wheel carrier with each other, and activating the first and second electrical machines to start the combustion engine.

A first controller includes a start control section and a passage determination section. After activating a second starter to start cranking, the start control section stops the operation of the second starter and starts the motor operation of the first starter at a predetermined timing. The passage determination section determines whether a predetermined passage conditional expression holds after cranking is started by the second starter. The start control section stops the operation of the second starter and starts the motor operation of the first starter if the passage conditional expression holds before the engine passes the first compression top dead center, regardless of whether the engine has passed the first compression top dead center.

A first controller includes a start control section and a passage determination section. After activating a second starter to start cranking, the start control section stops the operation of the second starter and starts the motor operation of the first starter at a predetermined timing. The passage determination section determines whether a predetermined passage conditional expression holds after cranking is started by the second starter. The start control section stops the operation of the second starter and starts the motor operation of the first starter if the passage conditional expression holds before the engine passes the first compression top dead center, regardless of whether the engine has passed the first compression top dead center.